]> git.kernelconcepts.de Git - karo-tx-linux.git/commitdiff
Btrfs: Make free space cache code generic
authorLi Zefan <lizf@cn.fujitsu.com>
Tue, 29 Mar 2011 05:46:06 +0000 (13:46 +0800)
committerLi Zefan <lizf@cn.fujitsu.com>
Mon, 25 Apr 2011 08:46:03 +0000 (16:46 +0800)
So we can re-use the code to cache free inode numbers.

The change is quite straightforward. Two new structures are introduced.

- struct btrfs_free_space_ctl

  We move those variables that are used for caching free space from
  struct btrfs_block_group_cache to this new struct.

- struct btrfs_free_space_op

  We do block group specific work (e.g. calculation of extents threshold)
  through functions registered in this struct.

And then we can remove references to struct btrfs_block_group_cache.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
fs/btrfs/ctree.h
fs/btrfs/extent-tree.c
fs/btrfs/free-space-cache.c
fs/btrfs/free-space-cache.h

index 2e61fe1b6b8cc76111f62c3f4b4aded03f7a0cce..d17e4a3b8bf7962b7fe18a7b66c811e6a676db1c 100644 (file)
@@ -830,9 +830,6 @@ struct btrfs_block_group_cache {
        u64 bytes_super;
        u64 flags;
        u64 sectorsize;
-       int extents_thresh;
-       int free_extents;
-       int total_bitmaps;
        unsigned int ro:1;
        unsigned int dirty:1;
        unsigned int iref:1;
@@ -847,9 +844,7 @@ struct btrfs_block_group_cache {
        struct btrfs_space_info *space_info;
 
        /* free space cache stuff */
-       spinlock_t tree_lock;
-       struct rb_root free_space_offset;
-       u64 free_space;
+       struct btrfs_free_space_ctl *free_space_ctl;
 
        /* block group cache stuff */
        struct rb_node cache_node;
index 31f33ba56fe823d40ecf308f32eb777315548376..904eae10ec65c2d40ced26c5bf634d5793a7b3b2 100644 (file)
@@ -105,6 +105,7 @@ void btrfs_put_block_group(struct btrfs_block_group_cache *cache)
                WARN_ON(cache->pinned > 0);
                WARN_ON(cache->reserved > 0);
                WARN_ON(cache->reserved_pinned > 0);
+               kfree(cache->free_space_ctl);
                kfree(cache);
        }
 }
@@ -4893,7 +4894,7 @@ wait_block_group_cache_progress(struct btrfs_block_group_cache *cache,
                return 0;
 
        wait_event(caching_ctl->wait, block_group_cache_done(cache) ||
-                  (cache->free_space >= num_bytes));
+                  (cache->free_space_ctl->free_space >= num_bytes));
 
        put_caching_control(caching_ctl);
        return 0;
@@ -8551,10 +8552,16 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                        ret = -ENOMEM;
                        goto error;
                }
+               cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
+                                               GFP_NOFS);
+               if (!cache->free_space_ctl) {
+                       kfree(cache);
+                       ret = -ENOMEM;
+                       goto error;
+               }
 
                atomic_set(&cache->count, 1);
                spin_lock_init(&cache->lock);
-               spin_lock_init(&cache->tree_lock);
                cache->fs_info = info;
                INIT_LIST_HEAD(&cache->list);
                INIT_LIST_HEAD(&cache->cluster_list);
@@ -8562,14 +8569,6 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                if (need_clear)
                        cache->disk_cache_state = BTRFS_DC_CLEAR;
 
-               /*
-                * we only want to have 32k of ram per block group for keeping
-                * track of free space, and if we pass 1/2 of that we want to
-                * start converting things over to using bitmaps
-                */
-               cache->extents_thresh = ((1024 * 32) / 2) /
-                       sizeof(struct btrfs_free_space);
-
                read_extent_buffer(leaf, &cache->item,
                                   btrfs_item_ptr_offset(leaf, path->slots[0]),
                                   sizeof(cache->item));
@@ -8580,6 +8579,8 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                cache->flags = btrfs_block_group_flags(&cache->item);
                cache->sectorsize = root->sectorsize;
 
+               btrfs_init_free_space_ctl(cache);
+
                /*
                 * We need to exclude the super stripes now so that the space
                 * info has super bytes accounted for, otherwise we'll think
@@ -8666,6 +8667,12 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
        cache = kzalloc(sizeof(*cache), GFP_NOFS);
        if (!cache)
                return -ENOMEM;
+       cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl),
+                                       GFP_NOFS);
+       if (!cache->free_space_ctl) {
+               kfree(cache);
+               return -ENOMEM;
+       }
 
        cache->key.objectid = chunk_offset;
        cache->key.offset = size;
@@ -8673,19 +8680,13 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
        cache->sectorsize = root->sectorsize;
        cache->fs_info = root->fs_info;
 
-       /*
-        * we only want to have 32k of ram per block group for keeping track
-        * of free space, and if we pass 1/2 of that we want to start
-        * converting things over to using bitmaps
-        */
-       cache->extents_thresh = ((1024 * 32) / 2) /
-               sizeof(struct btrfs_free_space);
        atomic_set(&cache->count, 1);
        spin_lock_init(&cache->lock);
-       spin_lock_init(&cache->tree_lock);
        INIT_LIST_HEAD(&cache->list);
        INIT_LIST_HEAD(&cache->cluster_list);
 
+       btrfs_init_free_space_ctl(cache);
+
        btrfs_set_block_group_used(&cache->item, bytes_used);
        btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid);
        cache->flags = type;
index 0e23bbabbba262f6ed3f95ccf4db50dcb1351e1a..d4fb4f077a7942ff5853202c94d31e82f8fcdb7c 100644 (file)
@@ -29,9 +29,7 @@
 #define BITS_PER_BITMAP                (PAGE_CACHE_SIZE * 8)
 #define MAX_CACHE_BYTES_PER_GIG        (32 * 1024)
 
-static void recalculate_thresholds(struct btrfs_block_group_cache
-                                  *block_group);
-static int link_free_space(struct btrfs_block_group_cache *block_group,
+static int link_free_space(struct btrfs_free_space_ctl *ctl,
                           struct btrfs_free_space *info);
 
 struct inode *lookup_free_space_inode(struct btrfs_root *root,
@@ -212,6 +210,7 @@ static int readahead_cache(struct inode *inode)
 int load_free_space_cache(struct btrfs_fs_info *fs_info,
                          struct btrfs_block_group_cache *block_group)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_root *root = fs_info->tree_root;
        struct inode *inode;
        struct btrfs_free_space_header *header;
@@ -417,9 +416,9 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
                        }
 
                        if (entry->type == BTRFS_FREE_SPACE_EXTENT) {
-                               spin_lock(&block_group->tree_lock);
-                               ret = link_free_space(block_group, e);
-                               spin_unlock(&block_group->tree_lock);
+                               spin_lock(&ctl->tree_lock);
+                               ret = link_free_space(ctl, e);
+                               spin_unlock(&ctl->tree_lock);
                                BUG_ON(ret);
                        } else {
                                e->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
@@ -431,11 +430,11 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info,
                                        page_cache_release(page);
                                        goto free_cache;
                                }
-                               spin_lock(&block_group->tree_lock);
-                               ret = link_free_space(block_group, e);
-                               block_group->total_bitmaps++;
-                               recalculate_thresholds(block_group);
-                               spin_unlock(&block_group->tree_lock);
+                               spin_lock(&ctl->tree_lock);
+                               ret = link_free_space(ctl, e);
+                               ctl->total_bitmaps++;
+                               ctl->op->recalc_thresholds(ctl);
+                               spin_unlock(&ctl->tree_lock);
                                list_add_tail(&e->list, &bitmaps);
                        }
 
@@ -471,16 +470,16 @@ next:
                index++;
        }
 
-       spin_lock(&block_group->tree_lock);
-       if (block_group->free_space != (block_group->key.offset - used -
-                                       block_group->bytes_super)) {
-               spin_unlock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
+       if (ctl->free_space != (block_group->key.offset - used -
+                               block_group->bytes_super)) {
+               spin_unlock(&ctl->tree_lock);
                printk(KERN_ERR "block group %llu has an wrong amount of free "
                       "space\n", block_group->key.objectid);
                ret = 0;
                goto free_cache;
        }
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 
        ret = 1;
 out:
@@ -503,6 +502,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                          struct btrfs_block_group_cache *block_group,
                          struct btrfs_path *path)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space_header *header;
        struct extent_buffer *leaf;
        struct inode *inode;
@@ -546,7 +546,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                return 0;
        }
 
-       node = rb_first(&block_group->free_space_offset);
+       node = rb_first(&ctl->free_space_offset);
        if (!node) {
                iput(inode);
                return 0;
@@ -851,30 +851,30 @@ out_free:
        return ret;
 }
 
-static inline unsigned long offset_to_bit(u64 bitmap_start, u64 sectorsize,
+static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
                                          u64 offset)
 {
        BUG_ON(offset < bitmap_start);
        offset -= bitmap_start;
-       return (unsigned long)(div64_u64(offset, sectorsize));
+       return (unsigned long)(div_u64(offset, unit));
 }
 
-static inline unsigned long bytes_to_bits(u64 bytes, u64 sectorsize)
+static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
 {
-       return (unsigned long)(div64_u64(bytes, sectorsize));
+       return (unsigned long)(div_u64(bytes, unit));
 }
 
-static inline u64 offset_to_bitmap(struct btrfs_block_group_cache *block_group,
+static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
                                   u64 offset)
 {
        u64 bitmap_start;
        u64 bytes_per_bitmap;
 
-       bytes_per_bitmap = BITS_PER_BITMAP * block_group->sectorsize;
-       bitmap_start = offset - block_group->key.objectid;
+       bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
+       bitmap_start = offset - ctl->start;
        bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
        bitmap_start *= bytes_per_bitmap;
-       bitmap_start += block_group->key.objectid;
+       bitmap_start += ctl->start;
 
        return bitmap_start;
 }
@@ -932,10 +932,10 @@ static int tree_insert_offset(struct rb_root *root, u64 offset,
  * offset.
  */
 static struct btrfs_free_space *
-tree_search_offset(struct btrfs_block_group_cache *block_group,
+tree_search_offset(struct btrfs_free_space_ctl *ctl,
                   u64 offset, int bitmap_only, int fuzzy)
 {
-       struct rb_node *n = block_group->free_space_offset.rb_node;
+       struct rb_node *n = ctl->free_space_offset.rb_node;
        struct btrfs_free_space *entry, *prev = NULL;
 
        /* find entry that is closest to the 'offset' */
@@ -1031,8 +1031,7 @@ tree_search_offset(struct btrfs_block_group_cache *block_group,
                                break;
                        }
                }
-               if (entry->offset + BITS_PER_BITMAP *
-                   block_group->sectorsize > offset)
+               if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
                        return entry;
        } else if (entry->offset + entry->bytes > offset)
                return entry;
@@ -1043,7 +1042,7 @@ tree_search_offset(struct btrfs_block_group_cache *block_group,
        while (1) {
                if (entry->bitmap) {
                        if (entry->offset + BITS_PER_BITMAP *
-                           block_group->sectorsize > offset)
+                           ctl->unit > offset)
                                break;
                } else {
                        if (entry->offset + entry->bytes > offset)
@@ -1059,42 +1058,47 @@ tree_search_offset(struct btrfs_block_group_cache *block_group,
 }
 
 static inline void
-__unlink_free_space(struct btrfs_block_group_cache *block_group,
+__unlink_free_space(struct btrfs_free_space_ctl *ctl,
                    struct btrfs_free_space *info)
 {
-       rb_erase(&info->offset_index, &block_group->free_space_offset);
-       block_group->free_extents--;
+       rb_erase(&info->offset_index, &ctl->free_space_offset);
+       ctl->free_extents--;
 }
 
-static void unlink_free_space(struct btrfs_block_group_cache *block_group,
+static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
                              struct btrfs_free_space *info)
 {
-       __unlink_free_space(block_group, info);
-       block_group->free_space -= info->bytes;
+       __unlink_free_space(ctl, info);
+       ctl->free_space -= info->bytes;
 }
 
-static int link_free_space(struct btrfs_block_group_cache *block_group,
+static int link_free_space(struct btrfs_free_space_ctl *ctl,
                           struct btrfs_free_space *info)
 {
        int ret = 0;
 
        BUG_ON(!info->bitmap && !info->bytes);
-       ret = tree_insert_offset(&block_group->free_space_offset, info->offset,
+       ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
                                 &info->offset_index, (info->bitmap != NULL));
        if (ret)
                return ret;
 
-       block_group->free_space += info->bytes;
-       block_group->free_extents++;
+       ctl->free_space += info->bytes;
+       ctl->free_extents++;
        return ret;
 }
 
-static void recalculate_thresholds(struct btrfs_block_group_cache *block_group)
+static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
 {
+       struct btrfs_block_group_cache *block_group = ctl->private;
        u64 max_bytes;
        u64 bitmap_bytes;
        u64 extent_bytes;
        u64 size = block_group->key.offset;
+       u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize;
+       int max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
+
+       BUG_ON(ctl->total_bitmaps > max_bitmaps);
 
        /*
         * The goal is to keep the total amount of memory used per 1gb of space
@@ -1112,10 +1116,10 @@ static void recalculate_thresholds(struct btrfs_block_group_cache *block_group)
         * sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
         * we add more bitmaps.
         */
-       bitmap_bytes = (block_group->total_bitmaps + 1) * PAGE_CACHE_SIZE;
+       bitmap_bytes = (ctl->total_bitmaps + 1) * PAGE_CACHE_SIZE;
 
        if (bitmap_bytes >= max_bytes) {
-               block_group->extents_thresh = 0;
+               ctl->extents_thresh = 0;
                return;
        }
 
@@ -1126,43 +1130,43 @@ static void recalculate_thresholds(struct btrfs_block_group_cache *block_group)
        extent_bytes = max_bytes - bitmap_bytes;
        extent_bytes = min_t(u64, extent_bytes, div64_u64(max_bytes, 2));
 
-       block_group->extents_thresh =
+       ctl->extents_thresh =
                div64_u64(extent_bytes, (sizeof(struct btrfs_free_space)));
 }
 
-static void bitmap_clear_bits(struct btrfs_block_group_cache *block_group,
+static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
                              struct btrfs_free_space *info, u64 offset,
                              u64 bytes)
 {
        unsigned long start, count;
 
-       start = offset_to_bit(info->offset, block_group->sectorsize, offset);
-       count = bytes_to_bits(bytes, block_group->sectorsize);
+       start = offset_to_bit(info->offset, ctl->unit, offset);
+       count = bytes_to_bits(bytes, ctl->unit);
        BUG_ON(start + count > BITS_PER_BITMAP);
 
        bitmap_clear(info->bitmap, start, count);
 
        info->bytes -= bytes;
-       block_group->free_space -= bytes;
+       ctl->free_space -= bytes;
 }
 
-static void bitmap_set_bits(struct btrfs_block_group_cache *block_group,
+static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
                            struct btrfs_free_space *info, u64 offset,
                            u64 bytes)
 {
        unsigned long start, count;
 
-       start = offset_to_bit(info->offset, block_group->sectorsize, offset);
-       count = bytes_to_bits(bytes, block_group->sectorsize);
+       start = offset_to_bit(info->offset, ctl->unit, offset);
+       count = bytes_to_bits(bytes, ctl->unit);
        BUG_ON(start + count > BITS_PER_BITMAP);
 
        bitmap_set(info->bitmap, start, count);
 
        info->bytes += bytes;
-       block_group->free_space += bytes;
+       ctl->free_space += bytes;
 }
 
-static int search_bitmap(struct btrfs_block_group_cache *block_group,
+static int search_bitmap(struct btrfs_free_space_ctl *ctl,
                         struct btrfs_free_space *bitmap_info, u64 *offset,
                         u64 *bytes)
 {
@@ -1170,9 +1174,9 @@ static int search_bitmap(struct btrfs_block_group_cache *block_group,
        unsigned long bits, i;
        unsigned long next_zero;
 
-       i = offset_to_bit(bitmap_info->offset, block_group->sectorsize,
+       i = offset_to_bit(bitmap_info->offset, ctl->unit,
                          max_t(u64, *offset, bitmap_info->offset));
-       bits = bytes_to_bits(*bytes, block_group->sectorsize);
+       bits = bytes_to_bits(*bytes, ctl->unit);
 
        for (i = find_next_bit(bitmap_info->bitmap, BITS_PER_BITMAP, i);
             i < BITS_PER_BITMAP;
@@ -1187,29 +1191,25 @@ static int search_bitmap(struct btrfs_block_group_cache *block_group,
        }
 
        if (found_bits) {
-               *offset = (u64)(i * block_group->sectorsize) +
-                       bitmap_info->offset;
-               *bytes = (u64)(found_bits) * block_group->sectorsize;
+               *offset = (u64)(i * ctl->unit) + bitmap_info->offset;
+               *bytes = (u64)(found_bits) * ctl->unit;
                return 0;
        }
 
        return -1;
 }
 
-static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache
-                                               *block_group, u64 *offset,
-                                               u64 *bytes, int debug)
+static struct btrfs_free_space *
+find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes)
 {
        struct btrfs_free_space *entry;
        struct rb_node *node;
        int ret;
 
-       if (!block_group->free_space_offset.rb_node)
+       if (!ctl->free_space_offset.rb_node)
                return NULL;
 
-       entry = tree_search_offset(block_group,
-                                  offset_to_bitmap(block_group, *offset),
-                                  0, 1);
+       entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
        if (!entry)
                return NULL;
 
@@ -1219,7 +1219,7 @@ static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache
                        continue;
 
                if (entry->bitmap) {
-                       ret = search_bitmap(block_group, entry, offset, bytes);
+                       ret = search_bitmap(ctl, entry, offset, bytes);
                        if (!ret)
                                return entry;
                        continue;
@@ -1233,33 +1233,28 @@ static struct btrfs_free_space *find_free_space(struct btrfs_block_group_cache
        return NULL;
 }
 
-static void add_new_bitmap(struct btrfs_block_group_cache *block_group,
+static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
                           struct btrfs_free_space *info, u64 offset)
 {
-       u64 bytes_per_bg = BITS_PER_BITMAP * block_group->sectorsize;
-       int max_bitmaps = (int)div64_u64(block_group->key.offset +
-                                        bytes_per_bg - 1, bytes_per_bg);
-       BUG_ON(block_group->total_bitmaps >= max_bitmaps);
-
-       info->offset = offset_to_bitmap(block_group, offset);
+       info->offset = offset_to_bitmap(ctl, offset);
        info->bytes = 0;
-       link_free_space(block_group, info);
-       block_group->total_bitmaps++;
+       link_free_space(ctl, info);
+       ctl->total_bitmaps++;
 
-       recalculate_thresholds(block_group);
+       ctl->op->recalc_thresholds(ctl);
 }
 
-static void free_bitmap(struct btrfs_block_group_cache *block_group,
+static void free_bitmap(struct btrfs_free_space_ctl *ctl,
                        struct btrfs_free_space *bitmap_info)
 {
-       unlink_free_space(block_group, bitmap_info);
+       unlink_free_space(ctl, bitmap_info);
        kfree(bitmap_info->bitmap);
        kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
-       block_group->total_bitmaps--;
-       recalculate_thresholds(block_group);
+       ctl->total_bitmaps--;
+       ctl->op->recalc_thresholds(ctl);
 }
 
-static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_group,
+static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
                              struct btrfs_free_space *bitmap_info,
                              u64 *offset, u64 *bytes)
 {
@@ -1268,8 +1263,7 @@ static noinline int remove_from_bitmap(struct btrfs_block_group_cache *block_gro
        int ret;
 
 again:
-       end = bitmap_info->offset +
-               (u64)(BITS_PER_BITMAP * block_group->sectorsize) - 1;
+       end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
 
        /*
         * XXX - this can go away after a few releases.
@@ -1284,24 +1278,22 @@ again:
        search_start = *offset;
        search_bytes = *bytes;
        search_bytes = min(search_bytes, end - search_start + 1);
-       ret = search_bitmap(block_group, bitmap_info, &search_start,
-                           &search_bytes);
+       ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes);
        BUG_ON(ret < 0 || search_start != *offset);
 
        if (*offset > bitmap_info->offset && *offset + *bytes > end) {
-               bitmap_clear_bits(block_group, bitmap_info, *offset,
-                                 end - *offset + 1);
+               bitmap_clear_bits(ctl, bitmap_info, *offset, end - *offset + 1);
                *bytes -= end - *offset + 1;
                *offset = end + 1;
        } else if (*offset >= bitmap_info->offset && *offset + *bytes <= end) {
-               bitmap_clear_bits(block_group, bitmap_info, *offset, *bytes);
+               bitmap_clear_bits(ctl, bitmap_info, *offset, *bytes);
                *bytes = 0;
        }
 
        if (*bytes) {
                struct rb_node *next = rb_next(&bitmap_info->offset_index);
                if (!bitmap_info->bytes)
-                       free_bitmap(block_group, bitmap_info);
+                       free_bitmap(ctl, bitmap_info);
 
                /*
                 * no entry after this bitmap, but we still have bytes to
@@ -1328,31 +1320,28 @@ again:
                 */
                search_start = *offset;
                search_bytes = *bytes;
-               ret = search_bitmap(block_group, bitmap_info, &search_start,
+               ret = search_bitmap(ctl, bitmap_info, &search_start,
                                    &search_bytes);
                if (ret < 0 || search_start != *offset)
                        return -EAGAIN;
 
                goto again;
        } else if (!bitmap_info->bytes)
-               free_bitmap(block_group, bitmap_info);
+               free_bitmap(ctl, bitmap_info);
 
        return 0;
 }
 
-static int insert_into_bitmap(struct btrfs_block_group_cache *block_group,
-                             struct btrfs_free_space *info)
+static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
+                     struct btrfs_free_space *info)
 {
-       struct btrfs_free_space *bitmap_info;
-       int added = 0;
-       u64 bytes, offset, end;
-       int ret;
+       struct btrfs_block_group_cache *block_group = ctl->private;
 
        /*
         * If we are below the extents threshold then we can add this as an
         * extent, and don't have to deal with the bitmap
         */
-       if (block_group->free_extents < block_group->extents_thresh) {
+       if (ctl->free_extents < ctl->extents_thresh) {
                /*
                 * If this block group has some small extents we don't want to
                 * use up all of our free slots in the cache with them, we want
@@ -1361,11 +1350,10 @@ static int insert_into_bitmap(struct btrfs_block_group_cache *block_group,
                 * the overhead of a bitmap if we don't have to.
                 */
                if (info->bytes <= block_group->sectorsize * 4) {
-                       if (block_group->free_extents * 2 <=
-                           block_group->extents_thresh)
-                               return 0;
+                       if (ctl->free_extents * 2 <= ctl->extents_thresh)
+                               return false;
                } else {
-                       return 0;
+                       return false;
                }
        }
 
@@ -1375,31 +1363,42 @@ static int insert_into_bitmap(struct btrfs_block_group_cache *block_group,
         */
        if (BITS_PER_BITMAP * block_group->sectorsize >
            block_group->key.offset)
-               return 0;
+               return false;
+
+       return true;
+}
+
+static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
+                             struct btrfs_free_space *info)
+{
+       struct btrfs_free_space *bitmap_info;
+       int added = 0;
+       u64 bytes, offset, end;
+       int ret;
 
        bytes = info->bytes;
        offset = info->offset;
 
+       if (!ctl->op->use_bitmap(ctl, info))
+               return 0;
+
 again:
-       bitmap_info = tree_search_offset(block_group,
-                                        offset_to_bitmap(block_group, offset),
+       bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
                                         1, 0);
        if (!bitmap_info) {
                BUG_ON(added);
                goto new_bitmap;
        }
 
-       end = bitmap_info->offset +
-               (u64)(BITS_PER_BITMAP * block_group->sectorsize);
+       end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
 
        if (offset >= bitmap_info->offset && offset + bytes > end) {
-               bitmap_set_bits(block_group, bitmap_info, offset,
-                               end - offset);
+               bitmap_set_bits(ctl, bitmap_info, offset, end - offset);
                bytes -= end - offset;
                offset = end;
                added = 0;
        } else if (offset >= bitmap_info->offset && offset + bytes <= end) {
-               bitmap_set_bits(block_group, bitmap_info, offset, bytes);
+               bitmap_set_bits(ctl, bitmap_info, offset, bytes);
                bytes = 0;
        } else {
                BUG();
@@ -1413,19 +1412,19 @@ again:
 
 new_bitmap:
        if (info && info->bitmap) {
-               add_new_bitmap(block_group, info, offset);
+               add_new_bitmap(ctl, info, offset);
                added = 1;
                info = NULL;
                goto again;
        } else {
-               spin_unlock(&block_group->tree_lock);
+               spin_unlock(&ctl->tree_lock);
 
                /* no pre-allocated info, allocate a new one */
                if (!info) {
                        info = kmem_cache_zalloc(btrfs_free_space_cachep,
                                                 GFP_NOFS);
                        if (!info) {
-                               spin_lock(&block_group->tree_lock);
+                               spin_lock(&ctl->tree_lock);
                                ret = -ENOMEM;
                                goto out;
                        }
@@ -1433,7 +1432,7 @@ new_bitmap:
 
                /* allocate the bitmap */
                info->bitmap = kzalloc(PAGE_CACHE_SIZE, GFP_NOFS);
-               spin_lock(&block_group->tree_lock);
+               spin_lock(&ctl->tree_lock);
                if (!info->bitmap) {
                        ret = -ENOMEM;
                        goto out;
@@ -1451,7 +1450,7 @@ out:
        return ret;
 }
 
-bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
+bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
                          struct btrfs_free_space *info, bool update_stat)
 {
        struct btrfs_free_space *left_info;
@@ -1465,18 +1464,18 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
         * are adding, if there is remove that struct and add a new one to
         * cover the entire range
         */
-       right_info = tree_search_offset(block_group, offset + bytes, 0, 0);
+       right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
        if (right_info && rb_prev(&right_info->offset_index))
                left_info = rb_entry(rb_prev(&right_info->offset_index),
                                     struct btrfs_free_space, offset_index);
        else
-               left_info = tree_search_offset(block_group, offset - 1, 0, 0);
+               left_info = tree_search_offset(ctl, offset - 1, 0, 0);
 
        if (right_info && !right_info->bitmap) {
                if (update_stat)
-                       unlink_free_space(block_group, right_info);
+                       unlink_free_space(ctl, right_info);
                else
-                       __unlink_free_space(block_group, right_info);
+                       __unlink_free_space(ctl, right_info);
                info->bytes += right_info->bytes;
                kmem_cache_free(btrfs_free_space_cachep, right_info);
                merged = true;
@@ -1485,9 +1484,9 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
        if (left_info && !left_info->bitmap &&
            left_info->offset + left_info->bytes == offset) {
                if (update_stat)
-                       unlink_free_space(block_group, left_info);
+                       unlink_free_space(ctl, left_info);
                else
-                       __unlink_free_space(block_group, left_info);
+                       __unlink_free_space(ctl, left_info);
                info->offset = left_info->offset;
                info->bytes += left_info->bytes;
                kmem_cache_free(btrfs_free_space_cachep, left_info);
@@ -1500,6 +1499,7 @@ bool try_merge_free_space(struct btrfs_block_group_cache *block_group,
 int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
                         u64 offset, u64 bytes)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *info;
        int ret = 0;
 
@@ -1510,9 +1510,9 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
        info->offset = offset;
        info->bytes = bytes;
 
-       spin_lock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
 
-       if (try_merge_free_space(block_group, info, true))
+       if (try_merge_free_space(ctl, info, true))
                goto link;
 
        /*
@@ -1520,7 +1520,7 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
         * extent then we know we're going to have to allocate a new extent, so
         * before we do that see if we need to drop this into a bitmap
         */
-       ret = insert_into_bitmap(block_group, info);
+       ret = insert_into_bitmap(ctl, info);
        if (ret < 0) {
                goto out;
        } else if (ret) {
@@ -1528,11 +1528,11 @@ int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
                goto out;
        }
 link:
-       ret = link_free_space(block_group, info);
+       ret = link_free_space(ctl, info);
        if (ret)
                kmem_cache_free(btrfs_free_space_cachep, info);
 out:
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 
        if (ret) {
                printk(KERN_CRIT "btrfs: unable to add free space :%d\n", ret);
@@ -1545,21 +1545,21 @@ out:
 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
                            u64 offset, u64 bytes)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *info;
        struct btrfs_free_space *next_info = NULL;
        int ret = 0;
 
-       spin_lock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
 
 again:
-       info = tree_search_offset(block_group, offset, 0, 0);
+       info = tree_search_offset(ctl, offset, 0, 0);
        if (!info) {
                /*
                 * oops didn't find an extent that matched the space we wanted
                 * to remove, look for a bitmap instead
                 */
-               info = tree_search_offset(block_group,
-                                         offset_to_bitmap(block_group, offset),
+               info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
                                          1, 0);
                if (!info) {
                        WARN_ON(1);
@@ -1574,8 +1574,8 @@ again:
                                             offset_index);
 
                if (next_info->bitmap)
-                       end = next_info->offset + BITS_PER_BITMAP *
-                               block_group->sectorsize - 1;
+                       end = next_info->offset +
+                             BITS_PER_BITMAP * ctl->unit - 1;
                else
                        end = next_info->offset + next_info->bytes;
 
@@ -1595,20 +1595,20 @@ again:
        }
 
        if (info->bytes == bytes) {
-               unlink_free_space(block_group, info);
+               unlink_free_space(ctl, info);
                if (info->bitmap) {
                        kfree(info->bitmap);
-                       block_group->total_bitmaps--;
+                       ctl->total_bitmaps--;
                }
                kmem_cache_free(btrfs_free_space_cachep, info);
                goto out_lock;
        }
 
        if (!info->bitmap && info->offset == offset) {
-               unlink_free_space(block_group, info);
+               unlink_free_space(ctl, info);
                info->offset += bytes;
                info->bytes -= bytes;
-               link_free_space(block_group, info);
+               link_free_space(ctl, info);
                goto out_lock;
        }
 
@@ -1622,13 +1622,13 @@ again:
                 * first unlink the old info and then
                 * insert it again after the hole we're creating
                 */
-               unlink_free_space(block_group, info);
+               unlink_free_space(ctl, info);
                if (offset + bytes < info->offset + info->bytes) {
                        u64 old_end = info->offset + info->bytes;
 
                        info->offset = offset + bytes;
                        info->bytes = old_end - info->offset;
-                       ret = link_free_space(block_group, info);
+                       ret = link_free_space(ctl, info);
                        WARN_ON(ret);
                        if (ret)
                                goto out_lock;
@@ -1638,7 +1638,7 @@ again:
                         */
                        kmem_cache_free(btrfs_free_space_cachep, info);
                }
-               spin_unlock(&block_group->tree_lock);
+               spin_unlock(&ctl->tree_lock);
 
                /* step two, insert a new info struct to cover
                 * anything before the hole
@@ -1649,12 +1649,12 @@ again:
                goto out;
        }
 
-       ret = remove_from_bitmap(block_group, info, &offset, &bytes);
+       ret = remove_from_bitmap(ctl, info, &offset, &bytes);
        if (ret == -EAGAIN)
                goto again;
        BUG_ON(ret);
 out_lock:
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 out:
        return ret;
 }
@@ -1662,11 +1662,12 @@ out:
 void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
                           u64 bytes)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *info;
        struct rb_node *n;
        int count = 0;
 
-       for (n = rb_first(&block_group->free_space_offset); n; n = rb_next(n)) {
+       for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
                info = rb_entry(n, struct btrfs_free_space, offset_index);
                if (info->bytes >= bytes)
                        count++;
@@ -1681,6 +1682,30 @@ void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
               "\n", count);
 }
 
+static struct btrfs_free_space_op free_space_op = {
+       .recalc_thresholds      = recalculate_thresholds,
+       .use_bitmap             = use_bitmap,
+};
+
+void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
+{
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
+
+       spin_lock_init(&ctl->tree_lock);
+       ctl->unit = block_group->sectorsize;
+       ctl->start = block_group->key.objectid;
+       ctl->private = block_group;
+       ctl->op = &free_space_op;
+
+       /*
+        * we only want to have 32k of ram per block group for keeping
+        * track of free space, and if we pass 1/2 of that we want to
+        * start converting things over to using bitmaps
+        */
+       ctl->extents_thresh = ((1024 * 32) / 2) /
+                               sizeof(struct btrfs_free_space);
+}
+
 /*
  * for a given cluster, put all of its extents back into the free
  * space cache.  If the block group passed doesn't match the block group
@@ -1692,6 +1717,7 @@ __btrfs_return_cluster_to_free_space(
                             struct btrfs_block_group_cache *block_group,
                             struct btrfs_free_cluster *cluster)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *entry;
        struct rb_node *node;
 
@@ -1713,8 +1739,8 @@ __btrfs_return_cluster_to_free_space(
 
                bitmap = (entry->bitmap != NULL);
                if (!bitmap)
-                       try_merge_free_space(block_group, entry, false);
-               tree_insert_offset(&block_group->free_space_offset,
+                       try_merge_free_space(ctl, entry, false);
+               tree_insert_offset(&ctl->free_space_offset,
                                   entry->offset, &entry->offset_index, bitmap);
        }
        cluster->root = RB_ROOT;
@@ -1727,12 +1753,13 @@ out:
 
 void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *info;
        struct rb_node *node;
        struct btrfs_free_cluster *cluster;
        struct list_head *head;
 
-       spin_lock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
        while ((head = block_group->cluster_list.next) !=
               &block_group->cluster_list) {
                cluster = list_entry(head, struct btrfs_free_cluster,
@@ -1741,57 +1768,58 @@ void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
                WARN_ON(cluster->block_group != block_group);
                __btrfs_return_cluster_to_free_space(block_group, cluster);
                if (need_resched()) {
-                       spin_unlock(&block_group->tree_lock);
+                       spin_unlock(&ctl->tree_lock);
                        cond_resched();
-                       spin_lock(&block_group->tree_lock);
+                       spin_lock(&ctl->tree_lock);
                }
        }
 
-       while ((node = rb_last(&block_group->free_space_offset)) != NULL) {
+       while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
                info = rb_entry(node, struct btrfs_free_space, offset_index);
-               unlink_free_space(block_group, info);
+               unlink_free_space(ctl, info);
                if (info->bitmap)
                        kfree(info->bitmap);
                kmem_cache_free(btrfs_free_space_cachep, info);
                if (need_resched()) {
-                       spin_unlock(&block_group->tree_lock);
+                       spin_unlock(&ctl->tree_lock);
                        cond_resched();
-                       spin_lock(&block_group->tree_lock);
+                       spin_lock(&ctl->tree_lock);
                }
        }
 
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 }
 
 u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
                               u64 offset, u64 bytes, u64 empty_size)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *entry = NULL;
        u64 bytes_search = bytes + empty_size;
        u64 ret = 0;
 
-       spin_lock(&block_group->tree_lock);
-       entry = find_free_space(block_group, &offset, &bytes_search, 0);
+       spin_lock(&ctl->tree_lock);
+       entry = find_free_space(ctl, &offset, &bytes_search);
        if (!entry)
                goto out;
 
        ret = offset;
        if (entry->bitmap) {
-               bitmap_clear_bits(block_group, entry, offset, bytes);
+               bitmap_clear_bits(ctl, entry, offset, bytes);
                if (!entry->bytes)
-                       free_bitmap(block_group, entry);
+                       free_bitmap(ctl, entry);
        } else {
-               unlink_free_space(block_group, entry);
+               unlink_free_space(ctl, entry);
                entry->offset += bytes;
                entry->bytes -= bytes;
                if (!entry->bytes)
                        kmem_cache_free(btrfs_free_space_cachep, entry);
                else
-                       link_free_space(block_group, entry);
+                       link_free_space(ctl, entry);
        }
 
 out:
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 
        return ret;
 }
@@ -1808,6 +1836,7 @@ int btrfs_return_cluster_to_free_space(
                               struct btrfs_block_group_cache *block_group,
                               struct btrfs_free_cluster *cluster)
 {
+       struct btrfs_free_space_ctl *ctl;
        int ret;
 
        /* first, get a safe pointer to the block group */
@@ -1826,10 +1855,12 @@ int btrfs_return_cluster_to_free_space(
        atomic_inc(&block_group->count);
        spin_unlock(&cluster->lock);
 
+       ctl = block_group->free_space_ctl;
+
        /* now return any extents the cluster had on it */
-       spin_lock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
        ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 
        /* finally drop our ref */
        btrfs_put_block_group(block_group);
@@ -1841,6 +1872,7 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
                                   struct btrfs_free_space *entry,
                                   u64 bytes, u64 min_start)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        int err;
        u64 search_start = cluster->window_start;
        u64 search_bytes = bytes;
@@ -1849,13 +1881,12 @@ static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
        search_start = min_start;
        search_bytes = bytes;
 
-       err = search_bitmap(block_group, entry, &search_start,
-                           &search_bytes);
+       err = search_bitmap(ctl, entry, &search_start, &search_bytes);
        if (err)
                return 0;
 
        ret = search_start;
-       bitmap_clear_bits(block_group, entry, ret, bytes);
+       bitmap_clear_bits(ctl, entry, ret, bytes);
 
        return ret;
 }
@@ -1869,6 +1900,7 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
                             struct btrfs_free_cluster *cluster, u64 bytes,
                             u64 min_start)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *entry = NULL;
        struct rb_node *node;
        u64 ret = 0;
@@ -1929,20 +1961,20 @@ out:
        if (!ret)
                return 0;
 
-       spin_lock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
 
-       block_group->free_space -= bytes;
+       ctl->free_space -= bytes;
        if (entry->bytes == 0) {
-               block_group->free_extents--;
+               ctl->free_extents--;
                if (entry->bitmap) {
                        kfree(entry->bitmap);
-                       block_group->total_bitmaps--;
-                       recalculate_thresholds(block_group);
+                       ctl->total_bitmaps--;
+                       ctl->op->recalc_thresholds(ctl);
                }
                kmem_cache_free(btrfs_free_space_cachep, entry);
        }
 
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 
        return ret;
 }
@@ -1952,6 +1984,7 @@ static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
                                struct btrfs_free_cluster *cluster,
                                u64 offset, u64 bytes, u64 min_bytes)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        unsigned long next_zero;
        unsigned long i;
        unsigned long search_bits;
@@ -2006,7 +2039,7 @@ again:
 
        cluster->window_start = start * block_group->sectorsize +
                entry->offset;
-       rb_erase(&entry->offset_index, &block_group->free_space_offset);
+       rb_erase(&entry->offset_index, &ctl->free_space_offset);
        ret = tree_insert_offset(&cluster->root, entry->offset,
                                 &entry->offset_index, 1);
        BUG_ON(ret);
@@ -2021,6 +2054,7 @@ static int setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
                                   struct btrfs_free_cluster *cluster,
                                   u64 offset, u64 bytes, u64 min_bytes)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *first = NULL;
        struct btrfs_free_space *entry = NULL;
        struct btrfs_free_space *prev = NULL;
@@ -2031,7 +2065,7 @@ static int setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
        u64 max_extent;
        u64 max_gap = 128 * 1024;
 
-       entry = tree_search_offset(block_group, offset, 0, 1);
+       entry = tree_search_offset(ctl, offset, 0, 1);
        if (!entry)
                return -ENOSPC;
 
@@ -2097,7 +2131,7 @@ static int setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
                if (entry->bitmap)
                        continue;
 
-               rb_erase(&entry->offset_index, &block_group->free_space_offset);
+               rb_erase(&entry->offset_index, &ctl->free_space_offset);
                ret = tree_insert_offset(&cluster->root, entry->offset,
                                         &entry->offset_index, 0);
                BUG_ON(ret);
@@ -2116,16 +2150,15 @@ static int setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
                                struct btrfs_free_cluster *cluster,
                                u64 offset, u64 bytes, u64 min_bytes)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *entry;
        struct rb_node *node;
        int ret = -ENOSPC;
 
-       if (block_group->total_bitmaps == 0)
+       if (ctl->total_bitmaps == 0)
                return -ENOSPC;
 
-       entry = tree_search_offset(block_group,
-                                  offset_to_bitmap(block_group, offset),
-                                  0, 1);
+       entry = tree_search_offset(ctl, offset_to_bitmap(ctl, offset), 0, 1);
        if (!entry)
                return -ENOSPC;
 
@@ -2158,6 +2191,7 @@ int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
                             struct btrfs_free_cluster *cluster,
                             u64 offset, u64 bytes, u64 empty_size)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        u64 min_bytes;
        int ret;
 
@@ -2177,14 +2211,14 @@ int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
        } else
                min_bytes = max(bytes, (bytes + empty_size) >> 2);
 
-       spin_lock(&block_group->tree_lock);
+       spin_lock(&ctl->tree_lock);
 
        /*
         * If we know we don't have enough space to make a cluster don't even
         * bother doing all the work to try and find one.
         */
-       if (block_group->free_space < min_bytes) {
-               spin_unlock(&block_group->tree_lock);
+       if (ctl->free_space < min_bytes) {
+               spin_unlock(&ctl->tree_lock);
                return -ENOSPC;
        }
 
@@ -2210,7 +2244,7 @@ int btrfs_find_space_cluster(struct btrfs_trans_handle *trans,
        }
 out:
        spin_unlock(&cluster->lock);
-       spin_unlock(&block_group->tree_lock);
+       spin_unlock(&ctl->tree_lock);
 
        return ret;
 }
@@ -2231,6 +2265,7 @@ void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
 int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
                           u64 *trimmed, u64 start, u64 end, u64 minlen)
 {
+       struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct btrfs_free_space *entry = NULL;
        struct btrfs_fs_info *fs_info = block_group->fs_info;
        u64 bytes = 0;
@@ -2240,52 +2275,50 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
        *trimmed = 0;
 
        while (start < end) {
-               spin_lock(&block_group->tree_lock);
+               spin_lock(&ctl->tree_lock);
 
-               if (block_group->free_space < minlen) {
-                       spin_unlock(&block_group->tree_lock);
+               if (ctl->free_space < minlen) {
+                       spin_unlock(&ctl->tree_lock);
                        break;
                }
 
-               entry = tree_search_offset(block_group, start, 0, 1);
+               entry = tree_search_offset(ctl, start, 0, 1);
                if (!entry)
-                       entry = tree_search_offset(block_group,
-                                                  offset_to_bitmap(block_group,
-                                                                   start),
+                       entry = tree_search_offset(ctl,
+                                                  offset_to_bitmap(ctl, start),
                                                   1, 1);
 
                if (!entry || entry->offset >= end) {
-                       spin_unlock(&block_group->tree_lock);
+                       spin_unlock(&ctl->tree_lock);
                        break;
                }
 
                if (entry->bitmap) {
-                       ret = search_bitmap(block_group, entry, &start, &bytes);
+                       ret = search_bitmap(ctl, entry, &start, &bytes);
                        if (!ret) {
                                if (start >= end) {
-                                       spin_unlock(&block_group->tree_lock);
+                                       spin_unlock(&ctl->tree_lock);
                                        break;
                                }
                                bytes = min(bytes, end - start);
-                               bitmap_clear_bits(block_group, entry,
-                                                 start, bytes);
+                               bitmap_clear_bits(ctl, entry, start, bytes);
                                if (entry->bytes == 0)
-                                       free_bitmap(block_group, entry);
+                                       free_bitmap(ctl, entry);
                        } else {
                                start = entry->offset + BITS_PER_BITMAP *
                                        block_group->sectorsize;
-                               spin_unlock(&block_group->tree_lock);
+                               spin_unlock(&ctl->tree_lock);
                                ret = 0;
                                continue;
                        }
                } else {
                        start = entry->offset;
                        bytes = min(entry->bytes, end - start);
-                       unlink_free_space(block_group, entry);
+                       unlink_free_space(ctl, entry);
                        kfree(entry);
                }
 
-               spin_unlock(&block_group->tree_lock);
+               spin_unlock(&ctl->tree_lock);
 
                if (bytes >= minlen) {
                        int update_ret;
@@ -2297,8 +2330,7 @@ int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
                                                         bytes,
                                                         &actually_trimmed);
 
-                       btrfs_add_free_space(block_group,
-                                            start, bytes);
+                       btrfs_add_free_space(block_group, start, bytes);
                        if (!update_ret)
                                btrfs_update_reserved_bytes(block_group,
                                                            bytes, 0, 1);
index 12b2b5165f8ad530f6b35abe6dc38ddd291aa634..a64a23fae1eb6a61aa4fbd81616db93e302b9fdd 100644 (file)
@@ -27,6 +27,25 @@ struct btrfs_free_space {
        struct list_head list;
 };
 
+struct btrfs_free_space_ctl {
+       spinlock_t tree_lock;
+       struct rb_root free_space_offset;
+       u64 free_space;
+       int extents_thresh;
+       int free_extents;
+       int total_bitmaps;
+       int unit;
+       u64 start;
+       struct btrfs_free_space_op *op;
+       void *private;
+};
+
+struct btrfs_free_space_op {
+       void (*recalc_thresholds)(struct btrfs_free_space_ctl *ctl);
+       bool (*use_bitmap)(struct btrfs_free_space_ctl *ctl,
+                          struct btrfs_free_space *info);
+};
+
 struct inode *lookup_free_space_inode(struct btrfs_root *root,
                                      struct btrfs_block_group_cache
                                      *block_group, struct btrfs_path *path);
@@ -45,6 +64,7 @@ int btrfs_write_out_cache(struct btrfs_root *root,
                          struct btrfs_trans_handle *trans,
                          struct btrfs_block_group_cache *block_group,
                          struct btrfs_path *path);
+void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group);
 int btrfs_add_free_space(struct btrfs_block_group_cache *block_group,
                         u64 bytenr, u64 size);
 int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,